Preservative treatment of timber.



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WILLIAM DENNISON CLARK, 0F PORTLAND, OREGON.

PRESERVATIVE TREATMENT OF TIMBER.

No Drawing.

To all whom it may concern Be it known that I, WILLIAM DENNISON CLARK, acitizen of the United States, and a resident of the city of Portland,county of Multnomali, State of Oregon, have invented a certain new anduseful Improvement in Preservative Treatment of Timber, of which thefollowing is a specification.

My invention relates to the treatment of timber by a liquid preservingagent so as to prevent decay'and the attack of insects; and the objectof my invention is to effect economy by preventing avoidable waste ofpreserving material in said treatment. For example, piling requiresprotection only of certain parts, and the application of the preservingmaterial'should be limited to such surfaces. I attain my object bycoating with a resisting paint-like substance the more porous surfaces,or the surfaces which are to resist more or less the penetration of thepreserving material, preferably using a substance especially compoundedfor such purpose and consisting of the following ingredients: commercialmagnesite or magnesium oxid 40'parts, powdered auxiliary filler,including any coloring matter if desired 12 parts, solution of magnesiumchlorid of the strength of about 35 degrees Baum 48 parts. p

I prefer to use for the auxiliaryfiller commercial asbestine pulp,which, as known, contains silicate of magnesium, the latter being aningredient which I find necessary to use in order to obtain goodresults; but, of course, I do notwish to be understood as limitingmyself to asbestine pulp, since other compounds which consist in part ofsilicate of magnesium may be used. When coloring matter is used, Ifindit advantageous to use of the latter only about two partsv to aboutten parts of asbestine pulp, or other compound containing silicate ofmagnesium. The solid matter is in the first instance thoroughlyintermingled,-and the chlorid solution is added shortly before using.The

strength of this preservative-resisting material is to be variedrelatively to the degree of resistance the preservative-resistingmaterial is to exert against the penetration of the preserving materialinto the timber being treated; and such variation in strength may beaccomplished by increasing and decreasing the strength of the chloridsolution, or by increasing .or decreasing the quantity of Specificationof Letters Patent.

Application filed July 3, 1914. Serial No. 848,939.

auxiliary filler, and relatively decreasing or increasing the quantityof the magnesium mud. The coloring matter is added in order to insureuniformity of color of those surfaces of the timber painted with mypreservative resisting material in comparison with the other surfacesafter the timber has been subjected to the preservative treat-- ment. Ipreferably use as the coloring matter black manganese or drop black.

The coating is applied by brush or spray to the surfaces which are toresist the penetration of the preserving material. I

A particularly'beneficial result is attained by my improved process, inconnection with the preservative treatment of timber having unequalporosity, for example, the ends and the sides'of railroad ties. Undersuch conditions the penetration of the preserving material is renderedmore uniform and equal, for by painting the more porous surfaces theresistance to penetration of such surfaces may be made'more equal tothat of the re- 'maining surfaces.

The compound above described is preferably used since it has theproperty of resisting solution by a preserving agent such as creosote,now commonly and preferably employed.

In the treatment of piling and green tim- "ber I use the followingprocess: I first immerse 'the timberpreferably boil the same-in thepreserving liquid for the purpose of driving out, in part, the moistureof the timber, in other words, artificially seasoning the timber. ""Ithen withdraw the' timber from the immersiomthen paint these surfaces ofthe timber" which are to resist the penetration of the preservativeliquid, and finally replace the timber in the preserving liquid andsubmit to pressure, so as to force the preserving liquid to penetratethose surfaces which have not been previously painted.

I claim 1. In the preservative treatment of timber, the method ofcontrolling the penetration of the preserving material into the timberwhich consists in coatingthe surfaces which are to resist thepenetration of the preserving material with a substance capable ofresisting-solution by the preserving agent, said coating beingappliedprevious to an immersion of the timber in the preserving material.

- r 2. In the preservative treatment of timber, the method ofcontrolling the penetration of the preserving material into the .timberwhich consists in coating 'the surfaces which are to resist thepenetration of the preserving material with a substance compounded ofmagnesium oxid, magnesium siliv cate and magnesium chlorid,substantially as set forth. A

A 3. In the preservative treatment of timber the method of controllingthe penetration of the preserving material into the timber whichconsists in coating the surfaces which are to resist the penetration ofthe preserving material with a compound made of oxid of magnesium, amineral auxiliary filler including magnesium silicate and a solution ofmagnesium chlorid, substantially as described; the proportion of theoxid, the filler and the chlorid solution being varied relatively to thedegree of resistance, to the preserving agent, desired to be imparted'tothe surfaces coated by said compound.

4. In the preservative treatment of timber, the method of firstimmersing the timber in the preserving liquid, for the purposeartificially seasoning the same, then Withdrawing the timber from thepreserving liquid, then painting the surfaces which are to resistfurther penetration of the preserving liquid, then replacing the timberin the preserving liouid and submitting to pressure, to thereby forcethe penetration of the preserving liquid into those surfaces which havenot been painted.

WILLIAM DENNIsoN CLARK.

Witnesses a WM. b. ScnMrrT, Cno L Lone.

